The present invention relates generally to electric circuit breakers and particularly to a remotely controllable residential circuit breaker-relay combination utilizing a single set of circuit interrupting contacts.
As electrical power distribution systems become more sophisticated, greater demands are being placed on the components thereof. This trend is most evident in industrial power distribution systems, where industrial circuit breakers are being equipped with more and more accessory functions. That is, industrial circuit breakers are increasingly being called upon to perform control and signal functions, in addition to their traditional circuit protective function. Thus, industrial circuit breakers are equipped with motor operator mechanisms to afford the capability of opening and closing the breaker contacts from a remote location automatically in response to conditions unrelated to circuit protection.
Recently, due largely to the concern for energy conservation, increasing emphasis is being placed on adding sophistication to residential and office power distribution systems. Computer-aided management of energy consumption in large buildings has been shown to be effective in dramatically reducing energy costs. A related concern is the limited electrical generating capacity which, at least in certain localities, is outstripped by consumer demands during peak times. Thus, utilities are considering the feasibility of widespread load shedding schemes enabling the utilities to controllably shed on a mass scale non-critical residential and office branch circuits at the onset of peak demand periods. Obviously, with such load shedding schemes in place, not only is energy conserved, but utilities and consumers alike are saved the high expense of additional generating capacity merely to satisfy the peak demand periods which typically are only several hours in duration.
To accommodate such a load shedding scheme, it is necessary to incorporate in each of the non-critical residential and office branch circuits to be shed some sort of remotely controlled switching device actuatable by the utility independently of the consumer to switch out the branch circuit load at the onset of a peak demand period and then switch in the branch circuit load when the peak demand period has subsided. Obviously, a conventional relay could be implemented to function as such a remotely controllable switching device to be selectively actuated in response to utility generated signals transmitted over power lines or phone lines. In many instances however, the branch circuits to be shed are already equipped with a form of switching device, that is, a circuit protective, residential molded case circuit breaker. It would therefore be manifestly desirable, both from standpoints of component cost and installation expediency, to adapt a residential molded case circuit breaker to serve both as a circuit protective device and a remotely controllable switching device.
It is accordingly an object of the present invention to provide a combination circuit protective residential circuit breaker and remotely controllable switching device.
An additional object is to provide a combination automatic residential circuit breaker-switching device of the above character which utilizes a single set of circuit interrupting contacts.
A further object of the present invention is to provide a circuit breaker-switching device combination of the above character, wherein the single set of circuit interrupting contacts are the stationary and movable contacts of a conventional residential molded case circuit breaker.
Another object of the present invention is to provide a circuit breaker-switching device combination of the above character wherein the remotely controlled actuation thereof may be manually over-ridden.
A still further object is to provide a circuit breaker-switching device combination of the above character which is conveniently installable in existing service entry panelboards.
Other objects of the invention will in part be obvious and in part appear hereinafter.